Siemens SINAMICS S150 NEMA, Руководство по эксплуатации

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Operation
6.12 Communication via MODBUS TCP
Enclosed Drives
Operating Instructions, 12/2018, A5E36652151A
423
Table 6- 58 Assignment of the Modbus register for general parameter access using DS47
Register Description Access Unit Scaling ON/OFF text or
value range
Data / parameter
40601 DS47 Control R/W - - - -
40602 DS47 header R/W - - - -
40603 DS47 data 1 R/W - - - -
… …
40722 DS47 data 120 R/W - - - -
Note
Limited value range
Modbus TCP registers have a maximum 16 bit width. The values of display parameters
(r parameters) cannot always be represented with 16 bits. In these particular cases, the
maximum value that can be represented is displayed.
•
Unsigned: 65535
• Signed min: -32768
•
Signed max: 32767
6.12.5 Write and read access using function codes
Function codes used
For data exchange between the controller and device, predefined function codes are used
for communication via Modbus.
The Control Unit uses the following Modbus function codes:
● FC 03: Holding register to read data from the inverter
● FC 06: Write single register to write to individual register
● FC 16: Write to multiple registers to write to several registers
Structure of a Modbus TCP message
Table 6- 59 Individual components, including Modbus Application Header (MBAP) and function code
Application Data Unit (ADU)
Modbus Application Header Protocol Data Unit (PDU
Transaction ID Protocol ID Length Unit ID FCode Data
2 bytes 2 bytes 2 bytes 1 byte 1 byte 0 ... 252 bytes